1. Field of Invention
This invention relates generally to aseptic packages for food products and systems and methods for aseptically packaging food products.
2. Description of Related Art
The aseptic packaging of processed products, such as foods, using flexible packaging materials, e.g., polymeric films, is commonly accomplished by various techniques. One such technique is sometimes referred to as a “bag-in-box.” In that technique aseptically processed products are filled by a machine into irradiated bags through a multi-component spout that is integral with the bag. Usually the spout is on the bag only to facilitate filling and thus brings no value to the finished package. The other common technique is accomplished on a “form, fill and seal” apparatus, wherein roll stock is used to produce the pouches.
While the prior art techniques and packages used thereby are generally suitable for their intended purposes they nevertheless leave much to be desired from one or more of the following standpoints, speed of operation, ability to handle a range of package sizes and shapes, complexity of the packages (e.g., necessity for an otherwise non-functional spout as a part of the package to effect its filling), susceptibility to leakage of the resulting packages.
In U.S. Pat. No. 5,210,993, whose disclosure is also incorporated by reference herein, there is disclosed a fill and seal machine for sealing plural pouches of a saddle-bag type configuration. Pouches of that type are disclosed in U.S. Pat. No. 5,237,799, whose disclosure is also incorporated by reference herein. A machine utilizing the teachings of those patents is commercially available from the assignee of this invention under the trade designation GL90. That machine is particularly suitable for the food-service industry since it can be used to fill flexible packages with a variety of products that are thermally processed after filling to render them shelf-stable. For example, the GL90 machine is versatile enough to be used in what are referred to as “hot-fill and hold” processes to create shelf-stable products. Products that fall into this category are high acidic, e.g., pH of 4.3 or lower, products and low water activity formulations. As presently configured the GL90 machine is not suitable to package low or high acid aseptically processed products at ambient temperatures direct from the process.
Numerous patents disclose aseptically sealed flexible packages and systems and methods for aseptically sealing products in flexible packages. For example, U.S. Pat. No. 4,194,622 (Lewis) discloses a sterilizable package wherein a slit extends along the front thereof from one side to the other, close to the bottom of the package. An adhesive layer is deposited over the entire length of the slit. A protective strip is disposed over the adhesive layer in order to protect it, thereby also sealing the slit. An object is inserted into the package by removing the strip and inserting the object through the slit. The package is sealed by folding it along a fold line located slightly above the adhesive to bring the adhesive into contact with the front of the package. The package is then sterilized.
U.S. Pat. No. 3,938,658 (Rohde) discloses a sterile pouch in which a film is drawn off a first roll and a narrow porous strip is drawn off a second roll. Spaced apart slits are provided in the film and the porous strip is superimposed upon and sealed to the film in a position covering the slits. The film is folded to form a pouch. The contents of the pouch are inserted from the bottom and the pouch is sealed. The pouch and contents are sterilized by a steriliant entering the pouch by way of the porous strip and the slit.
U.S. Pat. No. 5,551,781 (Wilkes) discloses a large sterilizable container having an access slit extending along a front surface thereof substantially from one side to the other at a location close to the top of the package. A porous membrane covers the access slit and a peelable interlayer is disposed between the front surface and the membrane without covering the slit. The contents' are inserted through the side of the container rather than through the access slit.
U.S. Pat. No. 5,868,244 (Ivanov) teaches a vented package wherein a slit-like vent opening 80 is provided with a gas permeable membrane to permit sterilizing gas to flow therethrough to sterilize the interior of the package and for evacuation of the gas after sterilization is complete. A seal is provided to close the vent opening after the sterilization process.
U.S. Pat. No. 4,035,981 (Braun) teaches an aseptic packing method which is of interest because it includes the use of dry radiation for sterilization of packing material. In the method taught by Braun, the packing material is shaped to form a tube that is sterilized by infrared and ultraviolet radiation and filled with a pre-sterilized food substance. The container is then stamped and sealed.
U.S. Pat. No. 4,022,324 (Schuster) teaches a sealed container wherein a breathable cover is bonded to a tray sheet. The cover comprises two panels forming an overlapping region that is covered with a breathable membrane disposed thereupon. The overlap between the two panels and the membrane form a passageway for sterilizing vapor that is impermeable to bacteria.
U.S. Pat. No. 3,783,581 (Pierce) discloses an aseptic packaging machine for packing food having an enclosed sterile chamber containing a plurality of operating stations. In the upper left of FIG. 1A, containers 48 are deposited from container storage hopper 50 and sterilized as they move vertically through the sterilization chamber 46. Thus, the containers are sterilized prior to filling, but they are not sealed at the time of sterilization. The containers are conveyed to a filling station where a sterile product is placed therein and a continuous strip of interconnected covers is placed into position in registry with the containers. The covers are heat sealed to the containers.
Other U.S. patents relating to this topic are: U.S. Pat. No. 3,481,100 (Bergstrom), U.S. Pat. No. 3,532,571 (Ausnit), U.S. Pat. No. 3,761,013 (Schuster), U.S. Pat. No. 3,884,012 (Ernstsson et al.), U.S. Pat. No. 3,947,249 (Egger), U.S. Pat. No. 4,008,851 (Hirsch), U.S. Pat. No. 4,057,144 (Schuster), U.S. Pat. No. 4,194,622 (Lewis), U.S. Pat. No. 4,223,512 (Buchner), U.S. Pat. No. 4,494,357 (DiGeronimo), U.S. Pat. No. 4,524,563 (Sassi), U.S. Pat. No. 4,686,814 (Yanase), U.S. Pat. No. 4,765,118 (Akutsu et al.), U.S. Pat. No. 4,782,646 (Nantin), U.S. Pat. No. 4,979,933 (Runge), U.S. Pat. No. 5,120,993 (van Boxtel), U.S. Pat. No. 5,228,271 (Wallace), U.S. Pat. No. 5,237,799 (van Boxtel), U.S. Pat. No. 5,310,262 (Robison et al.), U.S. Pat. No. 5,378,226 (Hanifl et al.), U.S. Pat. No. 5,606,847 (Joensson et al.), U.S. Pat. No. 5,776,045 (Bodolay et al.), U.S. Pat. No. 6,070,397 (Bachhuber), U.S. Pat. No. 6,079,184 (Cassou et al.), U.S. Pat. No. 6,085,491 (Bois), U.S. Pat. No. 6,098,800 (Bennish, Jr. et al.), U.S. Pat. No. 6,162,158 (Mercer et al.), U.S. Pat. No. 6,413,350 (Boschi), U.S. Pat. No. 6,419,825 (Hahmann et al.) and U.S. Pat. No. 6,510,669 (Bellei et al.). See also published U.S. Patent Application 2003/0014945 (Danby).